A couple of weeks ago I took my English Shepherd, Trailer, to a local herding instructor and he had his first exposure to sheep. My sister and her 3 year old Aussie, Izzy, went with us.
A man and his two boys were there buying some sheep and we spent a couple of hours waiting while sheep were sorted and loaded. Trailer was intensely interested in the two boys and all of the other dogs, and somewhat interested in the sheep. Izzy, on the other hand, was ALL ABOUT those sheep! She barked and whined the entire time we were waiting.
When the instructor took Trailer into the round pen with a few of the sheep, he didn't seem very interested. He was more worried about what all the other dogs were doing. After a few minutes, she let him and the sheep out into a larger pen with one of her Aussies. The Aussie began gathering the sheep and running circles around them. This got Trailer interested and he began running in circles around them also. The Aussie didn't listen very well and he would occasionally cut a single sheep from the herd. Trailer just kept circling the rest of them and making sure they stayed together in that spot. He kept looking at me to make sure what he was doing was okay, and when I called him off he came right to me. All of the other dogs had to be tied when it wasn't their turn to work but Trailer sat right by my side and watched as the other dogs worked.
When it was Izzy's turn the instructor had to spend several minutes just getting her settled down, but afterwards she did really well. Unlike Trailer, she wasn't interested in anything else BUT the sheep. I could really see the difference in the breeds. I'm so glad my dog has that ES "off switch".
We are taking the dogs to a herding clinic the first part of April and will start regular herding lessons after in a few weeks. I'm really looking forward to it, I think it's going to be a lot of fun.

Peace